A database administrator needs to encrypt a column of customer data in a relational database. The column contains many repeated values (e.g., country codes). The administrator wants to prevent an attacker from inferring patterns from the encrypted data. Which block cipher mode should be used?

AES in CTR mode with a fixed nonce.

A stream cipher with a static key.

AES in CBC mode with a random IV for each row.

A financial institution is implementing a key management policy for its encryption systems. The compliance team requires that keys be rotated regularly and that old keys remain usable to decrypt archived data. Which key management practice should be adopted?

Delete old keys immediately after rotation to reduce storage overhead.

Re-encrypt all archived data with the new key during each rotation.

Generate a new key for each rotation and retain old keys in a secure archive for decryption of historical data.

Use the same key indefinitely to avoid the complexity of key rotation.

Which of the following is a real-world application of encryption?

SSL/TLS for securing web traffic

DHCP for assigning IP addresses

HTTP for transferring web pages

A developer is implementing encryption for a real-time chat application. The messages are short and variable-length. The developer wants to avoid padding overhead and ensure that each message is encrypted independently. Which approach is most suitable?

Use a stream cipher like ChaCha20

Use a block cipher in CBC mode with PKCS#7 padding

Use a hash function to create a message digest

EC-CouncilNetwork Defense Essentials

Domain 6Objective 3

Data Encryption Techniques NDE Practice Questions (Page 7)

Part of the Cryptography, PKI, and Data Security domain, which makes up ~15% of our current practice bank.

44questions here

9free pages

7concepts

Questions 31–35

31application · medium
A database administrator needs to encrypt a column of customer data in a relational database. The column contains many repeated values (e.g., country codes). The administrator wants to prevent an attacker from inferring patterns from the encrypted data. Which block cipher mode should be used?
Select an answer first
32application · medium
A financial institution is implementing a key management policy for its encryption systems. The compliance team requires that keys be rotated regularly and that old keys remain usable to decrypt archived data. Which key management practice should be adopted?
Select an answer first
33foundation · easy
Which of the following is a real-world application of encryption?
Select an answer first
34application · easy
A healthcare organization needs to send encrypted patient records to a partner hospital. The partner hospital has published its public key on its website. The organization wants to ensure that only the partner can decrypt the records. Which key should the organization use to encrypt the records?
Select an answer first
35application · medium
A developer is implementing encryption for a real-time chat application. The messages are short and variable-length. The developer wants to avoid padding overhead and ensure that each message is encrypted independently. Which approach is most suitable?
Select an answer first

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